/*
   * TX4938 internal IDE driver
   * Based on tx4939ide.c.
   *
   * This file is subject to the terms and conditions of the GNU General Public
   * License.  See the file "COPYING" in the main directory of this archive
   * for more details.
   *
   * (C) Copyright TOSHIBA CORPORATION 2005-2007
   */
  
  #include <linux/module.h>
  #include <linux/types.h>
  #include <linux/ide.h>
  #include <linux/init.h>
  #include <linux/platform_device.h>
  #include <linux/io.h>
  
  #include <asm/ide.h>
  #include <asm/txx9/tx4938.h>
  
  static void tx4938ide_tune_ebusc(unsigned int ebus_ch,
  				 unsigned int gbus_clock,
  				 u8 pio)
  {
  	struct ide_timing *t = ide_timing_find_mode(XFER_PIO_0 + pio);
  	u64 cr = __raw_readq(&tx4938_ebuscptr->cr[ebus_ch]);
  	unsigned int sp = (cr >> 4) & 3;
  	unsigned int clock = gbus_clock / (4 - sp);
  	unsigned int cycle = 1000000000 / clock;
  	unsigned int shwt;
  	int wt;
  
  	/* Minimum DIOx- active time */
  	wt = DIV_ROUND_UP(t->act8b, cycle) - 2;
  	/* IORDY setup time: 35ns */
  	wt = max_t(int, wt, DIV_ROUND_UP(35, cycle));
  	/* actual wait-cycle is max(wt & ~1, 1) */
  	if (wt > 2 && (wt & 1))
  		wt++;
  	wt &= ~1;
  	/* Address-valid to DIOR/DIOW setup */
  	shwt = DIV_ROUND_UP(t->setup, cycle);
  
  	/* -DIOx recovery time (SHWT * 4) and cycle time requirement */
  	while ((shwt * 4 + wt + (wt ? 2 : 3)) * cycle < t->cycle)
  		shwt++;
  	if (shwt > 7) {
  		pr_warning("tx4938ide: SHWT violation (%d)
  ", shwt);
  		shwt = 7;
  	}
  	pr_debug("tx4938ide: ebus %d, bus cycle %dns, WT %d, SHWT %d
  ",
  		 ebus_ch, cycle, wt, shwt);
  
  	__raw_writeq((cr & ~0x3f007ull) | (wt << 12) | shwt,
  		     &tx4938_ebuscptr->cr[ebus_ch]);
  }
  
  static void tx4938ide_set_pio_mode(ide_hwif_t *hwif, ide_drive_t *drive)
  {
  	struct tx4938ide_platform_info *pdata = dev_get_platdata(hwif->dev);
  	u8 safe = drive->pio_mode - XFER_PIO_0;
  	ide_drive_t *pair;
  
  	pair = ide_get_pair_dev(drive);
  	if (pair)
  		safe = min_t(u8, safe, pair->pio_mode - XFER_PIO_0);
  	tx4938ide_tune_ebusc(pdata->ebus_ch, pdata->gbus_clock, safe);
  }
  
  #ifdef __BIG_ENDIAN
  
  /* custom iops (independent from SWAP_IO_SPACE) */
  static void tx4938ide_input_data_swap(ide_drive_t *drive, struct ide_cmd *cmd,
  				void *buf, unsigned int len)
  {
  	unsigned long port = drive->hwif->io_ports.data_addr;
  	unsigned short *ptr = buf;
  	unsigned int count = (len + 1) / 2;
  
  	while (count--)
  		*ptr++ = cpu_to_le16(__raw_readw((void __iomem *)port));
  	__ide_flush_dcache_range((unsigned long)buf, roundup(len, 2));
  }
  
  static void tx4938ide_output_data_swap(ide_drive_t *drive, struct ide_cmd *cmd,
  				void *buf, unsigned int len)
  {
  	unsigned long port = drive->hwif->io_ports.data_addr;
  	unsigned short *ptr = buf;
  	unsigned int count = (len + 1) / 2;
  
  	while (count--) {
  		__raw_writew(le16_to_cpu(*ptr), (void __iomem *)port);
  		ptr++;
  	}
  	__ide_flush_dcache_range((unsigned long)buf, roundup(len, 2));
  }
  
  static const struct ide_tp_ops tx4938ide_tp_ops = {
  	.exec_command		= ide_exec_command,
  	.read_status		= ide_read_status,
  	.read_altstatus		= ide_read_altstatus,
  	.write_devctl		= ide_write_devctl,
  
  	.dev_select		= ide_dev_select,
  	.tf_load		= ide_tf_load,
  	.tf_read		= ide_tf_read,
  
  	.input_data		= tx4938ide_input_data_swap,
  	.output_data		= tx4938ide_output_data_swap,
  };
  
  #endif	/* __BIG_ENDIAN */
  
  static const struct ide_port_ops tx4938ide_port_ops = {
  	.set_pio_mode		= tx4938ide_set_pio_mode,
  };
  
  static const struct ide_port_info tx4938ide_port_info __initconst = {
  	.port_ops		= &tx4938ide_port_ops,
  #ifdef __BIG_ENDIAN
  	.tp_ops			= &tx4938ide_tp_ops,
  #endif
  	.host_flags		= IDE_HFLAG_MMIO | IDE_HFLAG_NO_DMA,
  	.pio_mask		= ATA_PIO5,
  	.chipset		= ide_generic,
  };
  
  static int __init tx4938ide_probe(struct platform_device *pdev)
  {
  	struct ide_hw hw, *hws[] = { &hw };
  	struct ide_host *host;
  	struct resource *res;
  	struct tx4938ide_platform_info *pdata = dev_get_platdata(&pdev->dev);
  	int irq, ret, i;
  	unsigned long mapbase, mapctl;
  	struct ide_port_info d = tx4938ide_port_info;
  
  	irq = platform_get_irq(pdev, 0);
  	if (irq < 0)
  		return -ENODEV;
  	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
  	if (!res)
  		return -ENODEV;
  
  	if (!devm_request_mem_region(&pdev->dev, res->start,
  				     resource_size(res), "tx4938ide"))
  		return -EBUSY;
  	mapbase = (unsigned long)devm_ioremap(&pdev->dev, res->start,
  					      8 << pdata->ioport_shift);
  	mapctl = (unsigned long)devm_ioremap(&pdev->dev,
  					     res->start + 0x10000 +
  					     (6 << pdata->ioport_shift),
  					     1 << pdata->ioport_shift);
  	if (!mapbase || !mapctl)
  		return -EBUSY;
  
  	memset(&hw, 0, sizeof(hw));
  	if (pdata->ioport_shift) {
  		unsigned long port = mapbase;
  		unsigned long ctl = mapctl;
  
  		hw.io_ports_array[0] = port;
  #ifdef __BIG_ENDIAN
  		port++;
  		ctl++;
  #endif
  		for (i = 1; i <= 7; i++)
  			hw.io_ports_array[i] =
  				port + (i << pdata->ioport_shift);
  		hw.io_ports.ctl_addr = ctl;
  	} else
  		ide_std_init_ports(&hw, mapbase, mapctl);
  	hw.irq = irq;
  	hw.dev = &pdev->dev;
  
  	pr_info("TX4938 IDE interface (base %#lx, ctl %#lx, irq %d)
  ",
  		mapbase, mapctl, hw.irq);
  	if (pdata->gbus_clock)
  		tx4938ide_tune_ebusc(pdata->ebus_ch, pdata->gbus_clock, 0);
  	else
  		d.port_ops = NULL;
  	ret = ide_host_add(&d, hws, 1, &host);
  	if (!ret)
  		platform_set_drvdata(pdev, host);
  	return ret;
  }
  
  static int __exit tx4938ide_remove(struct platform_device *pdev)
  {
  	struct ide_host *host = platform_get_drvdata(pdev);
  
  	ide_host_remove(host);
  	return 0;
  }
  
  static struct platform_driver tx4938ide_driver = {
  	.driver		= {
  		.name	= "tx4938ide",
  	},
  	.remove = __exit_p(tx4938ide_remove),
  };
  
  module_platform_driver_probe(tx4938ide_driver, tx4938ide_probe);
  
  MODULE_DESCRIPTION("TX4938 internal IDE driver");
  MODULE_LICENSE("GPL");
  MODULE_ALIAS("platform:tx4938ide");